#4 Willian is the backbone of the Chelsea attack

Eden Hazard is usually rested for the Europa League games, while Pedro still competes for his position in the first team. This makes Brazilian winger Willian the only attacking player in the Chelsea team to play most of the matches in all sorts of competitions.
Willian is exceptional due to his pace and sprinting abilities, and this was on display last night in London when the Brazilian created the most chances on the pitch for Chelsea. He did not manage to score but assisted 2 of the 3 goals Chelsea scored, the third goal being a free kick from Barkley.
Willian has been the backbone of the Chelsea attack for a few seasons now, and is the only attacking player to have consistently performed under every manager Chelsea has had in the last 5 years.
The Brazilian midfielder is 30 years old now and when he starts to lose his pace due to his ageing, it is surely going to be a huge blow to the Chelsea lineup unless they find a potential replacement.